Fell Terrier~Old topic

We have a rescue dog. He's about 8yrs old is a black Fell Terrier. We first got him last autumn and were told that excessive scratching was due to the stress of settling into a new home - although he displated no other symptoms. The problem stopped the later in the year it got but began again as soon as we got to spring. It would now seem that this is an alergy we have tried all sorts to help alleviate the problem which is causing him, and in turn us, much distress. If anyone has a Fell Terrier or similar with this kind of problem: Have you found something that helps? Any ideas anyone please?? (A gluten free diet was a good start but not enough)